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First Dinosaurs

A Their enormous size meant that sauropods had to spend nearly all their time eating just to generate enough energy to stay alive. They probably fed mostly on coniferous trees, steadily munching their way through entire forests. It is this continuous eating that may have created what is known as a browse line, leaving trees bare of leaves below a certain level. in the early Cretaceous Period. Passion flowers, as well as flowering trees such as magnolia, beech, oak, maple, and walnut joined...

Which dinosaurs had a display of spikes A A group of dinosaurs called stegosaurs are characterized by their spiked tails and plated backs. Huayangosaurus was an early stegosaur, living some 20 million years before its more famous American relative Stegosaurus. It may have used its tail spikes to deter attack from larger carnivores.

How are dinosaur and bird bones similar Like birds, many dinosaurs had lightweight bones. Most animals have sturdy bones, but the bones of some dinosaurs and pterosaurs contained air-filled cavities to lessen the creature's weight. This was a vital asset for flying. There is another remarkable similarity the skeletons of early birds and some theropods are almost identical. A Paleontologists think birds evolved from a group of small, nimble, carnivorous theropods called maniraptorans. Members of...

A Not surprisingly the biggest dinosaurs the plant-eating sauropods laid some of the biggest eggs, although these were surprisingly small. A sauropod egg weighed about 11 lb 5 kg and was about 12 in 30 cm long. This is only about twice the size of an ostrich egg, and tiny compared to the size of the mother. A After hatching, dinosaur babies, like these Troodons, grew quickly most had to learn to defend themselves fast if they were to survive. Fossil evidence of hadrosaur young shows that they...

Could a carnivore make a meal of a plant-eater A big hunter, such as Allosaurus, would have had several advantages over lumbering plant-eater Stegosaurus. Not only was Allosaurus faster and more quick-witted, but it was also better equipped for killing. Allosaurus could slash out with its claws before sinking its razor-sharp teeth into its victim's flesh. Stegosaurus might have fought back by swiping out with its tail spikes, but that was unlikely enough to prevent it ending up as food for its...

A Some people think that herds of Pachyrhinosaurus used to trek about 2,200 miles 3,500 km from northern Alaska to Canada each autumn to escape the cold, dark winters. The herds would have returned to Alaska to feed on the lush plants that grew there in the spring. Evidence suggests that many types of plant-eating dinosaurs, including sauropods such as Barosaurus, lived together in herds. Being part of a group usually gives an individual animal greater protection against predators. It is also...

How long did dinosaurs rule 14 Were all dinosaurs the same 16 Dinosaurs were land-dwelling reptiles with long tails, clawed hands and feet, and scaly skin. Some walked on two legs, others on four. While some were meat-eaters, others munched on plants. Most people know what a dinosaur looks like from books and movies. But even experts are still unsure why dinosaurs survived when their rivals died out. It was probably their erect stance, the sheer size of the largest, such as Giganotosaurus, and...

Asteroid collision alone was the cause of the dinosaurs' extinction. Scientists also think that at the end of the Cretaceous Period there were numerous volcanic eruptions in India. These might have polluted the atmosphere with so much dust that the Sun's rays could not penetrate, and many creatures may have died of cold. A Throughout the time of the dinosaurs, the skies were filled with flying reptiles, but no pterosaurs survived the mass extinction. Reptiles would never take to the skies again...

Most experts estimate the top speed at between 10 25 mph 16 40 km h . Studies have shown that T. rex's legs weren't strong enough to absorb the pounding of its 6 tons of body weight at faster speeds. However, although T. rex was slower than the fastest dinosaurs such as Ornitholestes , it was fast enough to catch potential prey, such as lumbering plant-eater Triceratops. Tyrannosaurus rex would have needed about 300 lb 136 kg of meat each day to keep it supplied with energy. Scavengers such as...

How did hunters kill their prey 24 Did carnivores eat only meat 28 Put simply, a theropod was a flesh-eating dinosaur. This lizard-hipped group of dinosaurs included some of the largest carnivores ever to roam the Earth. Although theropods often had wimpy arms, they did have strong muscles to power their rear legs. They also had large teeth and strong jaws. Most, such as Carnotaurus, had three-toed feet ending in claws. Not all theropods were huge some were as small as chickens and survived by...

There were lumbering animals as big as buses. There were long-necked giants as tall as trees. There were massive predators that none could challenge And darting around their feet were nimble chicken-sized dinosaurs. Some dinosaurs were numerous others were rare. Some were plated, frilled, or horned others were merely weird looking. Chindesaurus, shown here, was a carnivorous dinosaur that lived during the late Triassic Period. All the different dinosaurs belonged to one of...

A A quadrupedal animal, such as Saltasaurus, is one that walks on all four legs. All sauropods, and most other plant-eating dinosaurs, were quadrupedal. This was probably because the plant-eaters had large stomachs that tended to pitch their bodies forward onto the front legs, making walking on only the back legs impossible. Front legs slightly shorter then back legs A One of the smallest known sauropods measured 20 ft 6 m from head to tail. Magyarosaurus and other smaller sauropods have been...